Method of pickling ferrous metals



Patented 1)....21, 1932 UNITED STATES PATENT OFFICE J RAYMOND MCE'LHANEY, OF VANDERGRIIT, PENNSYLVANIA, ASSIGNOR TO AMERICAN SHEET AND TIN PLATE COMPANY, A CORPORATION OF NEW J ERSEY METHOD OF PIGKLING- FEREOUS METALS No Drawing.

My invention relates to pickling ferrous metals and more particularly to pickling ferrous metal sheets and plates in removing lI'OIl.

oxid scale from the surfaces of such materials. v

The primary object of the invention is the provision of an improved step in the pickling operations whereby refractory and/.or stubborn varieties of scale such as, for example, those frequently encountered onsome alloy steels, are appreciably softened and loosened preparatory to being subjected to the action of the acid pickling solution.

The invention consists in the step of preliminarily immersing the materials to be pickled in hot water for an appreciable time interval and then pickling the materials by any of the known commercial methods. Preferably, the bath of. hot water will be maintained at a temperature of between 150 and v 212 degrees Fahrenheit and the time of im-. mersion of the articles to be treated will vary from about two minutes to about one hour.

Some of the advantages obtained by the use of my discovery are a saving in the amount of acid consumed, a reduction in the number of blistered sheets produced in the pickling operation, and a reduction in the time required for pickling by the methods used heretofore. s

Modifications in the details of .my improved method may be made without departing from the invention as defined in the appended claims. The eflec't of the hot water may be modified and/or increased by agita- 1931. Serial No. 544,927.

of, from about two minutes to about one hour preparatory to its introduction into the acid pickling solution.

In testimony whereof, I have hereunto set my hand.

JAMES RAYMOND MoELI-IANEY.

tion of it by steam or compressed air, by the addition of small quantities of acid of spent ickle liquor, of organic compounds, and of morganic salts and similar modifying agents. 1

I claim: r 1. In methods of pickling ferrous metal the step consisting in immersing the material to be pickled in water heated to between 150 and 212 degrees Fahrenheit preparatory to its introduction into the acid pickling solution. 2. In methods of pickling ferrous metal the step consisting in immersing the material to be pickled in water heated to between 150 to 212 degrees Fahrenheit for a time interval 

